particle

You want a physicist to speak at your funeral.
You want the physicist to talk to your family about the conservation of energy, so they will understand that your energy has not died. You want the physicist to remind your sobbing mother about the first law of thermodynamics; that no energy gets created in the universe, and that none dies.
You want your mother to know that all your energy, every vibration, every Btu of heat, every wave of every particle that was her beloved child remains with her in this world. You want the physicist to tell your weeping father that amid energies of the cosmos, you gave as good as you got.
And at one point you’d hope the physicist would step down from the pulpit and walk to your brokenhearted spouse there in the pew and tell him that all the photons that ever bounced off your face, all the particles whose paths were interrupted by your smile, by the touch of your hair, hundreds of trillions of particles, have raced off like children, their ways forever changed by you. And as your widow rocks in the arms of a loving family, may the physicist let her know that all the photons that bounced from you were gathered in the particle detectors that are her eyes, that those photons created within her constellations of electromagnetically charged neutrons whose energy will go on forever.
You can hope your family will examine the evidence and satisfy themselves that the science is sound and that they’ll be comforted to know your energy’s still around.
According to the law of the conservation of energy, not a bit of you is gone; you’re just less orderly.
—  Aaron Freeman
10

Nuclear Physics Might Hold The Key To Cracking Open The Standard Model

“Interestingly, this could also lead to a renewed interest in the search for glueballs, which would be the first ever direct evidence of a bound state of gluons in nature! If the exotic QCD predictions of tetraquarks and pentaquarks are borne out in our Universe, it stands to reason that glueballs should be there as well. Perhaps the existence of these composite particles will be verified at the LHC as well, with incredible implications for how our Universe works either way.”

Nuclear physics has, for decades now, been regarded less as a window into fundamental physics and more of a derived science. As we’ve discovered that nuclei, baryons, and mesons are all composite particles made out of quarks, antiquarks, and gluons, though, we’ve realized that there are other possible combinations that nature allows, that should exist. In recent years, we’ve discovered tetraquark and pentaquark states of quarks and antiquarks, and yet there should be even more. QCD, our theory of the strong interactions, predicts that a set of exotic states of bound gluons – known as a glueball – should exist. Finding them, or proving that they don’t exist, might be a way to crack open the Standard Model in an entirely new way.

Nuclear physics might, after all these years, hold the key to going beyond the current limitations of physics.

(#5) German Modal Particles - DOCH

What is a modal particle?

A word that stresses/emphasises something in a sentence or reflects the attitude a speaker is trying to convey. They are scarce in English (and various other languages), but to give an example take a look at ‘then’ in this sense:

“So how old are you then?”

If one was saying this to a child it could be seen as making the overall tone of the question more endearing and curious, not blunt.

German Modal Particle - Doch

This is one of the most common particles, doch is used a hell of a lot in German so you need to try and understand its meanings.

#1 - In statements it shows disagreement; unstressed = asking for confirmation and stressed = clearly contradicting.

Ex: Gestern hat es doch geschneit {unstressed}
It snowed yesterday, didn’t it?
Ex: Gestern hat es DOCH geschneit  {stressed}
[All the same], it DID snow yesterday.

#2 - When unstressed it can also be noting a reason for disagreement.

Ex: Die Ampel zeigt doch rot…
But the lights are red…

#3 - In commands doch can either:
—— i) Add a sense of urgency (strengthen with endlich, or immer in a negative sentence). 

Ex: Mach doch nicht [immer] so ein Gesicht!
Don’t keep making faces like that.

—— ii) Make a command more encouraging/advisory (add mal or ruhig to clarify this).

Ex: Kommen Sie doch [ruhig] morgen vorbei!
Why not drop by tomorrow?

#4 - In exclamations it emphasises surprise

Ex: Das ist doch die Höhe!
That really is the limit!

#5 - When using Subjunctive/Konjunktiv II it emphasises urgency.

Ex: Wenn er doch jetzt käme!
If only he would come NOW!

#6 - Probably one of the more common uses: When replying to a question, doch either contradicts a negative q. or gives a affirmation.

Ex: Bist du nicht zufrieden? Doch!
Aren’t you content?On the contrary I am (look how complicated english is now)
Ex: Kommt er bald? Doch!
Is he coming soon? Oh yes!

#7 - When used with nicht or nein it emphasies a negative reply.

Ex: Kann ich…? Nein doch!
Can i….? Certainly not!

I hope this helps and that I’ve explained it well enough… x).

Links to other modal particles posts: [Aber] [Allerdings] [Bloß] [Denn]

3

Excitation of atom by photon

Electron excitation is the transfer of a bound electron to a more energetic, but still bound state. This can be done by photoexcitation (PE), where the electron absorbs a photon and gains all its energy or by electrical excitation (EE), where the electron receives energy from another, energetic electron.

When an excited electron falls back to a state of lower energy, it undergoes electron relaxation. This is accompanied by the emission of a photon (radiative relaxation) or by a transfer of energy to another particle. The energy released is equal to the difference in energy levels between the electron energy states.

Image credit: teggor

10

Ask Ethan: What’s The Difference Between A Fermion And A Boson?

“Could you explain the difference between fermions and bosons? What differs from an integer spin and a half-integer spin?”

On the surface, it shouldn’t appear to make all that much difference to the Universe whether a particle has a spin in half-integer intervals (±1/2, ±3/2, ±5/2) or in integer intervals (0, ±1, ±2). The former is what defines fermions, while the latter defines bosons. This hardly seems like an important distinction, since intrinsic angular momentum is such a nebulous property to our intuitions, unlike, say, mass or electric charge. Yet this simple, minor difference carries with it two incredible consequences: one for the existence of distinct particles for antimatter and one for the Pauli exclusion principle, that are required for matter as we know it to be. Without these differences, and without these rules, it’s simply a matter of fact that the atoms, molecules and living things we see today wouldn’t be possible to create.

What’s the difference between fermions and bosons? A little difference goes a long way! Find out on this edition of Ask Ethan. (And thanks to the anonymous tumblr question that inspired it!)

8

How To Prove Einstein’s Relativity For Less Than $100

“But the fact that you can see cosmic ray muons at all is enough to prove that relativity is real. Think about where these muons are created: high in the upper atmosphere, about 30-to-100 kilometers above Earth’s surface. Think about how long a muon lives: about 2.2 microseconds on average. And think about the speed limit of the Universe: the speed of light, or about 300,000 kilometers per second. If you have something moving at the speed of light that only lives 2.2 microseconds, it should make it only 0.66 kilometers before decaying away. With that mean lifetime, less than 1-in-10^50 muons should reach the surface. But in reality, almost all of them make it down.”

Relativity, or the idea that space and time are not absolute, was one of the most revolutionary and counterintuitive scientific theories to come out of the 20th century. It was also one of the most disputed, with hundreds of scientists refusing to accept it. Yet with less than $100 and a single day’s worth of labor, there’s a way you can prove it to yourself: by building a cloud chamber. An old fishtank, some 100% ethyl or isopropyl alcohol, a metal base with dry ice beneath it and only a few other steps (see the full article for instructions) will allow you to construct a detector capable of seeing unstable cosmic particles. Yet these particles – and you’ll see about 1-per-second – would never reach Earth’s surface if it weren’t for relativity!

Come learn how you can validate Einstein’s first great revolution all for yourself, and silence the doubts in your mind. Nature really is this weird!

9

Break The Standard Model? An Ultra-Rare Decay Threatens To Do What The LHC Can’t

“Just by sitting around with a bunch of unstable atoms, waiting for them to decay and measuring the decay products to incredible accuracy, we have the potential to finally break the Standard Model. Neutrinos are already the one type of particle known to go beyond the original Standard Model predictions, with potential ties to dark matter, dark energy, and baryogenesis in addition to their mass problem. Discovering that they undergo this bizarre, never-before-seen decay would make them their own antiparticles, and would introduce Majorana Fermions into the real world. If nature is kind to us, a box full of radioactive material might at last do what the LHC can’t: shed light on some of the deepest, most fundamental mysteries about the nature of our Universe.”

Want to uncover the secrets to the Universe? Find out what particles and interactions there are beyond the Standard Model? The conventional approach is to take particles up to extremely high energies and smash them together, hoping that something new and exciting comes out. That’s a solid approach, but it has its limits. In particular, we haven’t seen anything new at the LHC other than the Higgs Boson, and might not even if we run it forever. But another, more subtle approach might yield heavy dividends: simply gathering a very large number of unstable atoms and looking for a special type of decay: neutrinoless double beta decay. If this decay actually occurs in nature, it would mean that neutrinos aren’t like the other particles we know of, but rather that neutrinos and antineutrinos are the same particles: Majorana particles!

What would all of this mean, and what would it teach us about our Universe? Find out about our simplest hope for going beyond the Standard Model today!

10

New LHC Results Hint At New Physics… But Are We Crying Wolf?

“What we’re seeing right now is a response from the community is what we’d expect to an alarm that’s crying “Wolf!” There might be something fantastic and impressive out there, and so, of course we have to look. But we know that, more than 99% of the time, an alarm like this is merely the result of which way the wind blew. Physicists are so bored and so out of good, testable ideas to extend the Standard Model – which is to say, the Standard Model is so maddeningly successful – that even a paltry result like this is enough to shift the theoretical direction of the field.”

The Standard Model of particle physics – with its six quarks in three colors, its three generations of charged leptons and neutrinos, the antiparticle counterparts to each, and its thirteen bosons, including the Higgs – describes all the known particles and their interactions in the Universe. This extends to every experiment ever performed in every particle accelerator. In short, this is a problem: there’s no clear path to what new physics lies beyond the Standard Model. So physicists are looking for any possible anomalies at all, at any theoretical ideas that lead to new predictions at the frontiers, and any experimental result that differs from the Standard Model predictions. Unfortunately, we’re looking at thousands of different composite particles, decays, branching ratios, and scattering amplitudes. Our standards for what’s a robust measurement and a compelling result need to be extremely high.

The newest LHCb results offer a hint of something interesting, but it’s got a long way to go before we can say we’ve discovered anything new. Come find out what we’ve seen today!